1. Field of the Invention
The present invention relates to a drum type washing machine, and more particularly, to a drum type washing machine having a drying device, in which a tub is directly connected to a cabinet.
2. Description of the Related Art
Washing machines may be broadly categorized into those having only a washing function and washing machines having washing and drying functions.
FIG. 1 is a side sectional view illustrating the inner structure of a conventional drum type washing machine having a drying device.
As shown in the drawing, the conventional drum type washing machine includes a tub 10 supported in a cabinet 2 by a spring 4 and a damper 6, a drum 20 installed in the tub 10 to accommodate laundry, a door 22 connected to the cabinet 2 to open and close the front side of the drum 20, a heater duct 30 installed at the upper side of the tub 10 to discharge hot air to the tub 10 and having a heater 26 and a blower 27, and a condensing duct 40 having one side connected to a lower side of the tub 10 and the other side connected to the heater duct 30 and condensing the humidity or moisture out of the circulated air.
A gasket 12, closely contacting the door 22 when the door 22 is closed and connected to the heater duct 30, is installed to the tub 10.
The tub 10 includes a motor 14 for rotating the drum 20.
A water supplying device 15, for supplying washing water or rinsing water into the tub 10 in washing mode or rinsing mode, is connected to the tub 10. The lower side of the tub 10 is connected to the drain device 16.
The drain device 16 includes a drain bellows 17 connected to the lower side of the tub 10, a drain pump 18 connected to the drain bellows 17, and a drain hose 19 connected to the drain pump 18.
The drum 20 has penetrating holes 22 formed in the circumference or in the rear side thereof, through which washing water and air pass.
The drum 20 includes a lifter 24 installed on the inner circumference of the drum 20 to agitate the laundry.
The blower 27 includes a circulation fan 28 rotatably installed in the heater duct 30 and a fan motor 29 installed in the heater duct 30 to rotate the circulation fan 28.
The condensing duct 40 is connected to a cooling water supply 42 for supplying cooling water to condense humidity contained in air being circulated while drying the laundry.
The cooling water supply 42 includes a cooling water valve 44 connected to an external hose and intermittently controlling the cooling water supplied through the external hose and a cooling water hose 45 for guiding the cooling water passed through the cooling water valve 44 into the condensing duct 40.
Operation of the conventional drum type washing machine having the structure as described above will be described as follows.
First, with the door 22 closed and the conventional drum type washing machine started after placing laundry in the drum 20, the conventional drum type washing machine supplies washing water through the water supply 15. The supplied washing water flows into the tub 10 and is introduced into the drum 20 through the penetrating holes 22 to wet the laundry.
After supplying the washing water, when the motor 14 is driven, the drum 20 is rotated and the laundry in the drum 20 is stirred within the drum 20, thus dirt on the laundry is separated from the laundry by the washing water. As such, after the washing cycle is completed, contaminated washing water in the tub 10 is drained out of the conventional drum type washing machine through the drain device 16.
Afterwards, the rinsing cycle for removing foam or suds remaining in the laundry is performed several times. During the rinsing cycle, the water supply 15 and the motor are controlled like the washing cycle to rinse the foam remaining in the laundry and the contaminated washing water containing foam is drained out of the conventional drum type washing machine through the drain device 16.
After several rinsing cycles, a dehydration cycle, for dehydrating the laundry using centrifugal force, is performed. The motor 14 is driven at a high speed to dehydrate the laundry and the washing water dehydrated from the laundry is drained out of the conventional drum type washing machine through the drain device 16.
Next, the conventional drum type washing machine performs a drying cycle for drying the washed laundry.
In the drying cycle, when the conventional drum type washing machine drives the motor 14 to rotate the drum 20, the laundry is agitated in the drum 20. The heater 26 is turned on to increase the temperature within the drum, the fan motor 29 is driven to rotate the circulation fan 28, and the cooling water valve 44 and the drain pump 18 are repeatedly turned on and off in a predetermined time interval.
Due to the rotation of the circulation fan 18, air in the drum 20 strikes the laundry to remove heat and moisture from the laundry and is transformed into low-temperature-and-high-humidity air. The transformed air passes through the penetrating holes 22 and flows between the drum 20 and the tub 10, and then enters the condensing duct 40. The low-temperature-and-high-humidity air is condensed by the cooling water while passing through the condensing duct 40.
The air passed through the condensing duct 40 is transformed into hot air by the heater 26 while passing through the heater 30. The hot air passes through the gasket 12 and is discharged into the inside of the gasket 16, and then is circulated in the drum 20. After that, the circulation is repeated to dry the laundry.
Meanwhile, the cooling water supplied to the condensing duct 40 passes through the condensing duct 40, is collected in the tub 10, and is periodically pumped by the drain pump 18 to be discharged from the conventional drum type washing machine.
As such, after performing the drying process using the hot air, the heater 26 is turned off, and only the drum 20 and the circulation fan 28 rotate to perform a dry process using cold air.
When the dry process using cold air is performed for a predetermined time, the conventional drum type washing machine stops the circulation fan 28 and the motor 14 to finish the drying process.
However, as described above, according to the conventional drum type washing machine having a drying device, since an inlet duct 31, connected to the heater duct 30, is connected to the gasket 12, a space between the cabinet 2 and the tub 10 is needed, so that the size of the conventional drum type washing machine is increased.
Moreover, since a part of air discharged through the inlet duct 31 is directly introduced into the tub 10 through an opening formed between the tub 10 and the drum 20 without passing through the interior of the drum 20 and is discharged, the efficiency of laundry drying operation is deteriorated.